This invention pertains generally to electric control systems and more particularly to a system and method for controlling the energization of ballasted loads such as flourescent and high intensity discharge lights.
With the energy crisis, people have become increasingly aware of energy saving measures, such as turning off unused electric lights and appliances and reducing the number of lights used to illuminate a given area. Electric lights are generally wired in banks in which a plurality of lights are energized by a circuit controlled and protected by a circuit breaker or fuse. The entire bank can be turned on and off as a whole with the switch or breaker, but individual control of the lights in the bank is not possible without additional wiring.
With incandescent lights, individual lamps can be removed or partially removed from their sockets to disconnect them from the energizing circuit, and they will draw no further energy. This technique cannot be successfully employed with flourescent lights or other ballasted loads. Even though the flourescent tubes are removed from their sockets, the ballasts remain connected to the circuit and continue to draw power. Prolonged energization of the ballast with the tubes removed can damage or destroy the ballast.